Just to avoid confusion, the document does not discuss super heavy at all. The document does provide detailed information about Starship launches, indicating that for the foreseeable future, no super heavy launches. It does include a completed super heavy at the shipyard though.

It shouldn't but Swarm got denied because the FCC thought their cubesats were too small to track. That doesn't strike me as a natural fit for an agency that's supposed to be responsible for telecommunications, not space traffic control. Who knows what other authorities they can invent for themselves? With Chevron deference as an active doctrine in Federal courts, executive agencies have had a fairly free hand to expand their powers and even ajudicate disputes and offenses. They are literally judge, jury and executioner in many areas of society. Though the courts at least are defending their own territory here and there which is more than we can say for Congress.

FAA retains jurisdiction over all American-flagged launches anywhere in the world, due largely to requirements of the OST. SeaLaunch for example. It's rather easier, however, to file paperwork with regards to damage probabilities when there's nothing around to damage.

The need for launches far from populated areas was regarding Earth-to-Earth trips between major cities. SpaceX's launch pads aren't near enough to populated areas for noise to be a launch-limiting issue from what I've heard.

The schedule for the SH launch pad in Florida is quite tight already. If they didn't even ask for permission in Texas it won't happen in time for the first flights, unless there is a major delay for them.

This is my thinking as well. They will obtain permission eventually, when it is time. This FAA change document describes a 2-3 year program with 3 phases and SX is already in phase 2, soon in phase 3. This must have been started quite some time ago and I suppose SX did not want to risk delaying this part by mixing in SH (which does have more impact on the environment) SS Mk1 may actually be lighter on the env than F9/FH (FAA seems to think so). When they receive the final version of this permission, they will submit a CR for SH :)

The simple reason I said so was that cost of transportation will far exceed building it anew (without the raptors & innards) at KSC.

The only obstacle to the permission for orbital Starship & Super heavy at Boca Chica are 12 house owners of Boca Chica (only two of them are permanent residents, rest use their houses as holiday home). Out of the two permanent residents one is a SpaceX fan.

When the time comes, SpaceX will buy them off or lure them to exchange their houses for a similar one at Padre Island.

When the time comes, SpaceX will buy them off or lure them to exchange their houses for a similar one at Padre Island.

Man if i was that resident....my price would be relocation into a similar priced property, and then free travel to and from mars(conditional on them succeeding in developing a rocket that can go to mars)

I always figured by the time they get ready to launch all up with Super Heavy they’d launch it from a floating platform, like an oil rig like thing, and float it out to be a safe distance from South Padre Island. I also maybe think I think that because every time I drive from SPI to Boca Chica, I drive past a place that builds oil rigs and I’m all like “they should totally launch from one”

Nice. One thing that hasn't been commented on here is the noise level comparison with Falcon 9 and Falcon heavy on page 17 in the PDF. The comparison uses dBA, which is weighted to account for the sensitivity of human hearing to different frequencies. Raptor seems to be a much quieter engine than Merlin, to human ears. Starship with 3 Raptor engines is between 13 and 18 dBA quieter than Falcon 9 with 9 Merlin engines. That means the acoustic power is at least factor 8 lower, while the thrust is about 2/3 of Falcon 9. That would make a SuperHeavy with a full complement of 31 Raptor engines only slightly louder than a Falcon 9 and quieter than Falcon Heavy.

The absolute noise power level should scale with the square root of the engine count, if each engine can be treated as an independent random noise generator. This would mean that doubling the number of engines would increase sound pressure by 3 dB. If it scaled linearly the increase would be 6 dB.

[Edit] The numbers in the PDF support this: tripling the number of Merlins increases sound pressure 5 dB.

Oh wow. That would be amazing! Assuming the 13 to 18 dBA difference between 3-engine SS and F9 is correct, that would put SH noise level significantly below F9 noise level (at least 9.8 3 dBA less noisy). I can hardly believe this is even possible.

I don't get how you arrived at this conclusion given that the other comment said:

Starship with 3 Raptor engines is between 13 and 18 dBA quieter than Falcon 9 with 9 Merlin engines. That means the acoustic power is at least factor 8 lower, while the thrust is about 2/3 of Falcon 9. That would make a SuperHeavy with a full complement of 31 Raptor engines only slightly louder than a Falcon 9

The comment you cited assumed that increasing the engine count by x results in an x-fold increase in perceived sound level (a linear relationship).

I questioned it and u/john_hasler said the sound level increases with the square root of the engine count. Assuming he’s right, increasing the number of raptors from 3 to 31 (by a facor of ~10) results in a 10dBA noise increase. Tanking the conservative estimate of a 3-engine SS being 13dBA below an F9 as a starting point, the 31-engine SH would still end up 3dBA below F9.

The engines aren't really white noise sources, though[1] . The Merlin and the Raptor will have different spectral power distributions and so A-weighted measurements might report the Merlin as being louder even though the Raptor might be producing more total sound power.

I half suspected that the A-weighting was the main reason for Raptor sounding quieter. If that was the case, it would help reduce noise pollution, but it wouldn't help with the physical damage done by the engine noise to launch infrastructure and itself (through reflected sound).

The counter-argument is that it would make launching Starship with three engines from a flat concrete launch pad similar to launching Falcon 9 without a water deluge system. If we see the Mk1 and Mk2 Starship prototypes launching from flat concrete pads, then it's not unreasonable to assume that Raptor is objectively quieter even without the A-weighting.

As I understand it, the power scales linearly with the number of engines. The amplitude (sound pressure) scales with the square root. The Wikipedia page about Decibel has a table that illustrates the relationship between power and amplitude. The 4-5 dBA difference between F9 and FH corresponds to a 3x increase in power.

DbA scale has a low frequency role off and doesn’t really take into account much of the sub frequencies from 50-60hz down. A rocket engine produces crazy amounts of low frequency which is one of the main reason for water dumps for sound pressure waves on launch sites, also low frequency travels a lot further than higher frequency. Would love to know what the DbC scale results are which take into account more sub frequencies for these rocket engines, with all their sub frequencies being included would be crazy and cool. Another cool test would be multiple measurements at certain intervals of distance to see the roll off

What's interesting, despite statement that phases 1 and 2 were to take a couple of years, they have apparently finished phase 2 in less than a year and aim to start phase 3 in a couple of months (with~20km hop).

Also, apparently, they were originally planning for 3km hop (probably 3-engine Hopper), but that plan, judging by Elon's tweets, is now ditched.

So, things seem to be going better than expected and the schedule is truly accelerated! Yay! That's unheard in the industry.

To avoid or minimize the chance of another nighttime test operation, SpaceX will now
start pre-test preparations the day prior to a planned test. The nominal T-0 for any test that involves
engine ignition is 1400.

The renders show the old DearMoon engine layout and we know the prototypes have central 3 engine clusters, but this render shows some other distinct features.

Notably there are separare smaller legs from the fins visible in all 3 ship renders. The fins still touch the ground, so I think these are supplemental. I think this serves to allow the wings to be at any angle during landing and for Starship to still have a stable base. It would also reduce the loads that have to be carried through the wing hinges assuming they still move similarly.

I think this make sense because it is a lot more convenient that way (you can put it in a hangar, or on a boat, you don't need a crane to inspect it…) But I think they are not doing that yet because first it needs to be assembled to have some kind of structural rigidity.

Calling the brush fire "large" is shoddy journalism. It was very small compared to other brush fires and only large when compared to campfires or bonfires.

Calling it a large brush fire is close to a lie

Its a little issue in the grand scheme of things but all of these small errors add up.

Anyway, this should surprise no one, SpaceX didn't anticipate how long the boca chica would take to set up, how fast starshio/BFR would get to flight operations, or expected F9/FH demand would be higher and propose another Falcon launch pad.

Or maybe they always planned south texas site was for starship/BFR but they didn't think they could get approval for this future rocket but could for an existing one.

Texan brush fires, and other rural brush fires. It was an acre or so of grass, so small that the local fire department just let it burn out rather then fight it. What was "large" about it? What's a small brush fire then?

Pressurizing the fuel and oxidizer tanks with gaseous methane or oxygen should be doable. But how to spin up the turbines reliably during engine startup? Helium has traditionally been used, a gas that's hard to obtain on Mars. Can nitrogen be used instead, at a high enough pressure? Or electric motors as with the Rutherford engine?

So if my read of this is correct, with the 150m hop we're already in phase 2 and most everything described in this document has already been built. I don't think there's much to be gleaned from details such as Starship being laid on it's side, since we already know that's not how it worked out.

/u/FlyNSubaruWRX Looks like you were actually right about them lying Starship on its side! SpaceX continues to impress and innovate. I guess Starship has enough performance margin to allow for the shell to be built strong enough for this.

Yes, but you have Working At Heights issues, everything is out in the weather, etc, and it makes it difficult to use things like submerged arc welding.
It does mean you don't have to figure out a way to maintain roundness, however.

It does mean you don't have to figure out a way to maintain roundness, however.

That's the thing of it, I'd imagine. It's much less risky to just stack the rings and have less forces at play to cause buckling and uh, denting, for lack of a better word. Once you lay it down maneuvering everything around for construction becomes a bit more difficult.

Yeah, there'll be pros and cons either way. I would have chosen to lay it down but I'm not hung up on it (maybe Elon said no simply because he didn't want to buy another expensive jig). Whatever works.

Nice, although after I read the comments, what others had said made sense about the unfinished test vehicles would collapse on its self. It makes sense once all the supports and what have you are finished it would be able to be laid down.

Is there any information on how this impacts long-term plans for SpaceX in Boca Chica? I have family down in Brownsville, and if this has long term implications, I may want to consider moving back in a few years.

With pure renewable electricity I don't see why we couldn't make it on Earth as well instead of mining fossil methane. By the time we get there there may even be a subsidy or other benefit since we'd essentially be launching carbon into space...

I'm not sure where I read it. I think it was on twitter about a year or so ago. Elon's point was that it could be close to carbon nuetral, as the CO2 would be taken out of the air. CO2 and H20 are the main combustion byproducts.

SpaceX also claimed it was environmentally irresponsible to dump stages into the sea, but they still do it when they don't want to recover them. I'm not sure you can read too much into their comments about producing methane on Earth any time soon...

Yes, but at one point they were having a go at other launch companies, because it isn't environmentally responsible to drop stages into the sea and that they should land them and dispose of them properly. SpaceX now have the ability to land their stages, but they still never land them in order to dispose of them properly, only to reuse them.

My point being that SpaceX haven't got a history of spending money for environmental reasons - I'm expecting them to continue to use fossil fuels until it becomes more expensive than producing the methane themselves cleanly.

Wouldn't adding mercaptan to the methane (or LNG) cause contamination during combustion? Pipeline natural gas is dried before compression for CNG, and I thought LNG is shipped with no oderizor. (I was part of some projects where excess methane from LNG fueling operations had to be odorized before being added to a domestic Natural Gas line.)

A bit of casual research indicates that LNG can be odorized (with some difficulty) but usually isn't. Firemen would know that, though, so labeling the truck LNG when it's really pure methane shouldn't cause them a problem.

I wouldn't think that 25 ppm would be a problem but perhaps the sulfur in most odorants could cause corrosion.

I wonder how hard it is to transition from bp methane to subcooled? I know they were able to do it within the same engine family in Merlin. Just curious what has to change (I know the flow rates change, so maybe piping diameters?)

The sketches show Starship in the horizontal position. If accurate, there has to be a strongback coming soon to Boca Chica to set the vehicle vertical on the launch pad. My impression was that both Starship and Super Heavy would be built in the vertical orientation and moved around the launch/landing site also in the vertical position via those nifty self-propelled modular transporters (SPMTs), like the one already used to move Starhopper in the vertical position from its construction area to its launch pad. Maybe that's changed and I didn't get the memo.

Thanks for the info. Good to know. That's going to be one impressive crane. IIRC the total height of the Starship/Super Heavy stack is about 380 ft (116 m), a bit taller than the Saturn V stack.

Setting SH on the launch pad is pretty straightforward once you have a large enough crane since the height of the launch platform above ground level is probably a lot less than 100 ft (30.5 m). Starship dry mass is 85,000 kg (187,393 lb) and its height is 55-meters (180 ft), about the same height as Super Heavy. So the crane has to lift an 85 mt load that's 55 meters tall such that the bottom end of Starship is 55+ meters above ground to mate with the top of Super Heavy. The hoisted mass is not that great, but the lift height is not trivial.

In figure 6 on page 9. Top right corner there is a crane. If you go to NSF forums, there are pictures of the pieces for a giant white crane that members have found a complete crane type it looks to be. The frame is still on site in Boca Chica unassembled.